Re : NI 488.2

[NI_Device_user_sb]

Bonjour,

je travaille actuellement à l'élaboration d'un système utilisant des cartes PCI-GPIB+.

Un de mes objectifs est de capturer les trames gpib provenant d'un Controller GPIB, ce dernier envoyant des commandes à différents instruments.

Je souhaiterai savoir s'il est possible avec les fonctions NI488.2 de récuperer les données en ayant des correspondances avec les adresses visées.


J'ai testé la carte en la mettant en mode Listen Only à l'aide de la fonction ibconfig() mais j'ai l'impression que connaître l'adresse n'est pas possible.

De plus, j'ai testé NI-Device, qui me permet de configurer virtuellement des instruments. J'ai différents buffers pour chaque instruments visé mais la technique de réception employée dans ce logiciel est limitée à des END en mettant la ligne EOI dans un état spécifique.

En vous remerciant par avance.

[NI_Device_user_sb]

Hi,

maybe in English it would be better.
I'm currently designing an application with 2 PCI-GPIB+ boards.

My first question is : IS it possible to get all data over the gpib bus with NI488.2 functions. I need to switch between differents addresses to get all interesting data.

I tried  ibrd() with different addresses set by ibpad()
I think I could implement a round robin algorithm?

I also tried with NI VISA but I can't set the  interface's address.


Finally I tried NI-Device but this is not the main goal of this software. As I understand it's a software which helps to develop 488.2 Instruments but I can't use to terminate GPIB transactions on EOS characters. SO if you have any suggestions or opinion about that.

I would be pleased to ear from you soon. (sorry for my english which is not great)

[Dennis_Knutson]

Could you explain why you are using two different GPIB boards? Only one can be the master so you may be having problems there. Typically, you only use a single GPIB controller with a daisy chain or star configuration of cables. You then address each instrument that you want to do a read/write.

[NI_Device_user_sb]

Sure I can explain. Here is my goal : I have a calculator which is the Controller In Charge and some intruments connected to it. I have to separate them with my solution which consists of one personal computer with 2 GPIB boards. It is as a bridge, I think so. I have to capture all data sent by the CIC wich are destinated to all instruments and then translating some commands in order to replace old instruments by most recent ones.

[Dennis_Knutson]

If I understand correctly, you might be better off using a version of the NI PCI-GPIB controller that is also a bus analyzer. You can then monitor/capture all of the bus traffic.

[NI_Device_user_sb]

My goal is to capture all data on gpib bus for all addresses. I think I can't capture all data with standard NI 488.2 functions because I have to set one GPIB address for the interface so, I can miss other frames that are destinated to other addresses. NI-Device seems to be good in this case, it can have different buffers for different addresses. ??

[Dennis_Knutson]

No, you can't capture all data with the standard 488 routines. That is why I suggested a bus analyzer. It is designed to capture all traffic to all instrument addresses. If the sending controller used an NI GPIB board and NI software, you could use NI-Spy but it doesn't sound like this is an option.

[Dennis_Knutson]

I didn't notice it before, but you say you already have the PCI-GPIB+. In MAX, you can turn on analyzer mode.

Message Edited by Dennis Knutson on 04-22-2008 08:09 AM

[NI_Device_user_sb]

I'm not sure to understand your answers. What I need is to capture all data. I've got a PCI-GPIB+ board which is delivered with an Analyser(it's a software). As (approximately) this software, I need to capture data on Program Message Terminator which needs to be configurable(EOS, EOI,byte count etc...) NI PCI-GPIB board are the same thing without this software?no?

[NI_Device_user_sb]

So,I think you've not understood my needs. In MAX, I can launch GPIB Analyzer. But that's not what I want. I need to code a software in C or C++ doing relatively the same thing as GPIB Analyzer. Capturing all datas.